Approve source

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations supply destructiveHint=true and idempotentHint=false, and the description goes well beyond them: it discloses that credits are charged, that a paused estimate run resumes as a real indexing run, and that subsequent uploads index without further approval. The confirmation and no-auto-resubmit guidance adds concrete operational safety context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two compact sentences with the state transition front-loaded and no filler. The second sentence's caution is justified given the credit-charging and non-idempotent behavior, though it is slightly more advisory than strictly definitional.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutating, credit-spending, non-idempotent operation with no output schema, the description supplies the preconditions, effects, cost implication, and retry guidance an agent needs. Nothing material is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so account, confirm, and source_id are already documented in the schema. The description reinforces the confirm semantics ('explicit confirmation is required') but adds no syntax or format detail beyond the structured fields, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Approve a `draft` source') and then enumerates the resulting state transitions (draft -> active, paused estimate resumes, credits charged). This is far more specific than the title 'Approve source' and lets an agent distinguish it from siblings like create_brain_source or list_brain_sources.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Establishes the precondition ('a `draft` source'), the confirmation requirement, and a retry caveat ('never resubmit unknown outcomes automatically'). It stops short of explicitly naming an alternative tool to use instead when the source is not a draft, so it is clear context without full when/when-not routing.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.